Question

KAssignment 8 3 of 4 Problem 17.101 PartA The spool has a mass of 120 kg and a radius of gyration of kG 0.3 m. (Figure ) lf the coeficents of static and kin teh t nat A are μ, 0.2 and m 0.15, respectively determine the angular acceleration of the spoolP 48 N Express your answer to three significant figures and include the appropriate units IA Figure 1 of 1 Value rad/s Submit Previous Answers Bequest Answer Incorrect; Try Again; 2 attempts remaining 250 m 400 mm Next > Provide Feedback

Answer 1

Given m = 120 kg, us = 0.2 p = 48 N Kg = 0.3m, mu m = 0.15 free body diagram of spool for no slip aG = 0.4 alpha F_A Subsetequalto mu s NA FA Subsetequalto (0.2) (1177) FA Subsetequalto 235.44 N taking sigma fy implies NA - mg = 0 implies NA = (120)(9.81)a = 1177 N sigma Fx implies P + FA = 120aG 48 + FA = 120(0.4 alpha) sigma mG = I alpha = 48 (0.29) - FA(0.4) = [120(0.3)^2] alpha \r\n therefore 12 - 0.4 FA = 10.8 alpha using above two equations FA - 48 alpha = -48 0.4 FA + 10.8 alpha = 12 solving these two equation we get alpha = 1 - 1 rad/s^2 FA = 4.8 N Hence condition also satisfied fA = 4.8 subset 235.4 N